In Act 2, Scene 3, Malcolm and Lennox arrive at Macbeth's castle in the morning. They speak with the Porter then meet with Macbeth. Macduff asks if the king (Duncan) is awake; Macbeth replies, "Not yet." Lennox notes to the storm the night before. The violent winds and owl's screeching symbolize to the sounds of murder.

Macduff returns to Lennox and Macbeth, claiming that Duncan has been murdered. Lady Macbeth enters, acting as if she has no idea what is going on:

What's the business,

That such a hideous trumpet calls to parley

The sleepers of the house? Speak, speak. (II.iii.76-78)

Macbeth also acts as surprised at this is horrible discovery:

Had I but died an hour before this chance

I had lived a blessed time, for from this instant

There's nothing serious in mortality. (II.iii.87-89)

Macbeth is saying that he wishes he would have died before hearing this news of murder. Hearing such terrible news, there is nothing worth living for ("nothing serious in mortality.")

Lennox tells Duncan's sons, Malcolm and Donalbain, that Duncan's servants who slept in his chamber seem to be the murderers. The bloodied daggers were found under their pillows. Immediately, Macbeth admits to killing them to avenge Duncan. Banquo suggests they try to figure out the real reason why the king was killed. They all agree to dress and meet in the hall to discuss it. However, Malcolm and Donalbain agree to go to England and Ireland respectively, because they fear for their lives and don't want to appear is if they are not grieving: "To show an unfelt sorrow is an office / Which the false man does easy. I'll to England." (II.iii.32-33)

Because Malcolm and Donalbain flee the scene, it "puts upon them / Suspicion of the deed." (II.iv.26-27) Macbeth is crowned king and he condemns Donalbain and Malcolm as being involved in Duncan's murder:

We hear our bloody cousins are bestowed

In England and Ireland, not confessing

Their cruel parricide, filling their hearers

With strange invention. (III.i.31-34)

Completing the cover-up, Macbeth has directed all suspicion on Malcolm and Donalbain.